Spark-plug.



0. G. WINES'IOOK.

SPARK PLUG.

APPLICATION FILED SEPT. 1,1908.

'Snuwtoz, Wizmiazk r V I Patented Oct. 26; 1909.

wd/a Q urnrn 'tion is a removable member 3 OFFICE,

OTTO CHARLES VJINES'IOCK, 0F PERKINSVILLE, VERMONT.

SPARK-PLUG.

Application filed September 1, 1908.

Specification of Letters Patent.

Patented Oct. 26, 1909. Serial No. 451,213

To allwhom it may concern:

Be it known that I, OTTO C. Nmns'roon, a c tizen of the United States, residing at Perkinsville, in the county of Windsor and State of Vermont, have invented a new and useful Spark-Plug, of which the following is a specification.

I This invention has reference to improvemerits in spark plugs and its object is to provlde for the better insulation and securing of the stem carrying the inner or central ter-' minal.

The invention also includes means for the ready adjustment of the spark gap, the presa consideration of the following detail dc scription taken in connection with the ac companyg drawings forming a part of this specification in which drawings,

Figure l is a longitudinal section of the improved spark plug-with parts shown in elevation; Figs. 2, 3, 4t, 5, 6 and 7 are detail views of difi'erent forms of the terminal end ofthe spark plug." I

Referring to the drawings there is shown a member 1 in the general form usually provided for the cylindrical shell of a spark plug of the jump spark type and this shell has one end shaped into a neck 2 externally screw threaded to enter the usual screw threaded passage provided in the walls oi the ignition chamber of an explosive engine for the introduction of the spark plug,

. Throu h' the shell there is an axial Jassage ofless diameter where it extends through the neck 2 than at the other end of the shell 1, and between these two portions the axial passage is conical as indicated.

Both ends of the body portion are open and normally located within this body porexteriorly shaped to seat in the axial passage througl'i the member 1 and of such length as to extend slightly beyond each end of the said memher 1. The removable member 3 providedat diametrically opposite points handles lloy means of which it may be inserted in or removed from the body member .1, the

handles entering and being locked by suitably shaped slots in the body member 1, which slots however form no part of the present invention and are not shown in detail 1n the drawings.

The interior or the'removable member 3 is iorm'ed with an axial passage which may be cylindrical at the lower end as indicated at 5 and then is made conical or tapering as indicated at (3 to the other or upper end of said removable member 3.

Fitted within the tapering portion 6 or" the bore of the removable member 3 is a tapering sleeve 7 of insulating material of equal thickness throughout so that the interior of the sleeve tapers like the exterior thereof, that is to say the'interior walls of the sleeve and the exterior Walls thereof are parallel one to the other.v

The sleeve 7 receives the tapered end 8 of a stem 9013' conducting material extending beyond the smaller end of the sleeve 7 and there is threaded as shown at 10 to receive a suitable thumb nut 11 by means of which a suitable conductor may be electrically connected to the stem 9. The sleeve 7 extends for a distance beyond the corresponding end of the removable member 3 and there receives an insulating block 12 to the outer end of which is; applied one or more washers 13 and a clamp nut 14 screwed on the threaded end 10 of the stem 9. The nut let serves to force the washers 13 against the insulating block 12 andthe latter against the corresponding end of the removable seetion 3. At the same time the stem 9 1S drawn toward the nut 14; and this causes the tapered end of the stem. 9 to tightly clamp the sleeve 7 in the tapered bore (3 oi? the member 3.

The larger end of the tapered portion 8 of the stem 9 does not extend to the cone sponding end of the insulating sleeve 7 and this larger .end is preferably bored and.

tapped to form a threaded socket 15 for the reception of the threaded end of a rod 16 extending centrally through the smaller end of the removable member 3 and beyond said end, and there carries a disk 17 which may be riveted to the rod 16 in the form shown in Fig.1 or may be otherwise attached thereto. in the structure'shown in Fig. l the disk 17 is formed with an annular series of projecting teeth 18 extending laterally from one facevo'f the disk and in operatlve relation to the corresponding end of tile removable member 3, which end is annular and projects beyond the body 1 at this point.

The threaded socket 15 is of such depth and the rod 16 of such length that the said rod may be screwed into or out of said socket and so bring the teeth 18 closer to or farther from the active end of the removable member 3. This active end which is designated in the drawings by the reference. numeral 19 becomes the fixed electrode of the spark plug while the toothed disk 17 be comes the adjustable elect-rode. By this means not only may the length of the spark gap be adjusted at will but each time it is adjusted the points are brought opposite new portions of the fixed electrode, and thus the most eliicient conditions are present each time the electrode 17 is adjusted. Furthermore, by providing a considerable space between the active end 19 of the member 3 and the corresponding end of the insulation and tapered portion 8 of the stem 9, there is formed a chamber which is subjected to the alternate action of compression and rareficationv as the piston of the engine reciprocates. The result of this is that there is more or less circulation established in the portion 5 of the bore of the member 3, and this tends to keep this portion of the electrode free from the accumulation of any deleterious matters.

Instead of forming the disk 17 with teeth it may be formed as a plane disk as shown at 20 in Fig. 2, although in this case the sparking points are not localized as in the case of the structure shown in Fig. 1.

Instead of using a plane disk as shown in Fig. 2, the disk may be somewhat-dished as indicated at 21 in Fig. 3, the surface presented toward the fixed electrode 19 being convex so that any oil or other matter which may reach this convex surface will tend to readily gravitate therefrom and thereby the formation of soot between the electrode caused by the burning of the oil is prevented.

Instead of making the stem 16 carrying the electrodes 17, 20 or 21 adjustable in the stem section 8 the rod may be made in one piece with said stem as shown at 22 in Fig. 4, and the free end of said rod may be threaded as indicated at 23 and a plane disk electrode 24: may be screwed thereon and held in adjusted positions by means of a clamp nut 25 applied to the threaded end 23.

Instead of using a plane electrode 2i screwed upon the threaded end 28 of the rod extension, 22 a convex electrode 26 similar to the electrode 21 of Fig. 3 may be screwed upon the threaded end of the rod 22 as shown in Fig. 6, and the clampnut 25 will then hold this electrode 26 in any adjusted position.

Since there are certain advantages in using toothed electrodes, or at least one of down against the washer 13 and insulating block 12. There is thus provided a very broad bearing surface for the rather fragile insulating material and without bringing too great pressure to bear upon this material a perfectly reliable gas tight joint is formed in this part of the structure and this joint is not at all liable to injury from the high pressures generated within the explosion chamber of the engine.

It is to be observed that the movable electrode is of substantially the same diameter as the external diameter of the fixed electrode 19 so that the sparks must pass in a direction parallel with the axis of the movable electrode. Thispermits the lengthening or shortening of the spark gap by simply moving the electrode from or toward the fixed electrode 19 in the structure of Fig. 1 or the fixed electrode 27 in the structure of Fig. 5.

In Fig. 7 the tapered end 8 is shown at 28 as split longitudinally and the stem 16 has its threaded end 29 also tapered so that when screwed into the end 8 of the stem 9 the said end 8 is spread and so tightly forces the taperedsleeve 7 against the walls of the members 3. To facilitate the screwing of the stem 16 into the end 8 the free or outer end of said stem is notched or slotted as shown at 30 to receive a screw-driver or other suitable tool.

The structure of Fig. 7 may be used in connection withany of the forms of electrodes shown in the other figures, the electrode 31 shown in Fig. 7 being threaded to adjust on the threaded end 32 of the stem 16 and is there held by a nut 33.

What is claimed is l. A spark plug having a central electrode stem with one end tapering, a removable member for said electrode, a tapering sleeve of insulating material interposed between the tapering end of the electrode stem and the removable member, said sleeve having parallelinner and outer walls, an annular fixed electrode, and a disk-like movable electrode exterior to and of greater diameter than the inner diameter of the fixed electrode said movable electrode being adjustable bodily to and from the fixed electrode in the direction of the longitudinal axis of relative to the said fixed electrode with the spark gap substantially constant throughout the active portions of the electrodes.

2. A spark plug having an annular fixed electrode, a central insulated stem extending through and beyond the fixed electrode and there threaded, and a disk-like electrode with a convex inner face, said electrode being threaded to screw upon said stem to and from the active end. of the fixed electrode.

3. A spark plug having an external 0011- ducting member, a tapered sleeve of 1nsulating material interior thereto, a taper inernber interior to sald sleeve and provided with a split threaded socket, a stern with a taper threaded end adapted to enter the said threaded socket, and an electrode carried by the other end of the stern.

A spark plug having an external conducting member, a tapered sleeve of insulating material therein, a taper member interior to said sleeve and provided with a split threaded socket, a stem with a tapered threaded end adapted to enter the said threaded socket and an electrode adjustable longitudinally on said stem.

A. spark plug havin an external con ducting member, a tapered sleeve of insulating material interior thereto, a taper member interior to said sleeve and provided with a split threaded socket, a stem with a taper threaded end adapted to enter the said 

